The Bateman bipolar prosthesis has been used by the authors since 1974. The purpose of
this study is to determine whether the implant functions as a bipolar device or as a unipolar
hemiarthroplasty, which may cause damage to the acetabulum. Of 478 hips replaced from
1973 to 1983, 19 with acetabular changes were randomly selected to evaluate the response
of the prosthesis. From the 11 cases with protrusio at the time of surgery, six showed
thickening of the acetabular wall, while no changes were observed during ten years follow …